Expansible bit.



Patented Nov. 20, 1900.. J; P; LAVIGNE.. EXPANSIB LE BIT.

No. 662,l99.

(Application filed A (No Model.)

UNrTnn STATES ATENT OFFICE.

JOSEPH PETER LAVIGNE, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TO JOHN J. TOWER, OF NEW YORK, N. Y.

EXPANSIBLE BIT.

SPECIFICATION forming pa-rt of Letters Patent No. 662,199, dated November 20, 1900.

Application filed April 2, 1900- Serial No. 11,148. (No model.)

To aZZ whom it may concern.-

Be it known that LJOSEPH PETER LAVIGNE, of New Haven, in the county of New Haven and State of Connecticut,have invented a new Improvement in Expansible Bits; and I do hereby declare the following, when taken in connection with the accompanying drawings and the numerals of reference marked thereon, to bea full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure 1, a view in elevation of an expansible bit constructed in accordance with my invention; Fig. 2, a view thereof in side elevation with the clamping-plate in its clamping position and the cutter in section; Fig. 3, a view of the bit partly in side elevation and partly in vertical section, showing the clamping-plate in the position into which it is forced by the spring when the clamping-screw has been turned back preparatory to releasingthe cutter; Fig. 4:, a less comprehensive view of the bit in vertical section, showing the releasing of the cutter by rocking the clampingplate upon the head of the clampingscrew; Fig. 5, a detached perspective view of the clamping-plate; Fig. 6, a broken View in front elevation of amodification of my improvement; Fig. 7, a broken view of such modification in vertical section, taken on a line passing transversely through the cutter.

My invention relates to an improvement in expansible bits, the object being to produce a simple, strong, and durable bit,constructed with particular reference to adjusting the position of the transVersely-arranged sliding cutter without removing the clamping-plate by means of which it is held in place against longitudinal movement.

With this end in View my invention consists in a bit having a spring coacting with the clamping-plate to cause the same to retain its hold upon the cutter when the clampingscrew is reversed preparatory to adjusting the cutter.

My invention further consists in certain details of construction and combinations of parts, as will be hereinafter described, and pointed out in the claims.

In carrying out my invention as herein shown I locate a spring-socket 2 in the upper portion of the head 3, formed at the lower end of the shank 4 of the bit, the said socket entering the said head from the bottom of the upper end of the recess 5, formed in the head for the reception of the clamping-plate 6, which is secured inplace by the clampingscrew '7, which passes through acountersunk hole 8, formed in the plate, and intoa screwthreaded hole 9, passing through the head at a point in line with but below the springsocket 2. The said socket receives a spring 17, the function of which will appear later on. The lower edgeof the clam ping-plate is formed with a bevel 10, arranged to coact with the beveled upper edge 11 of the transverselyarranged sliding cutter 12, the lower edge of which is formed with an undercut rib 13, engaging with the undercut lower wall 14 of the recess 5. The back of the cutter as thus formed constitutes a dovetail, whereby it is held in place. The cutter itself is provided upon its outer face with graduations 15, which are usedin conjunction with the guiding-mark 16 upon the clamping-plate in setting the cutter. The upper end of the plate 6 is provided with a rounded centrally-arranged centeringlug 18,Which enters a recess 19, corresponding to it in shape and leading out of the upper end of the clamping-plate recess 5. This lug acts to prevent the plate from swinging upon the clamping-screw as upon a center and so maintains the guiding-mark 16 upon the plate in its right relation to the other members of the tool, for if this mark were shifted by the swiveling of the plate one way or the other the value of the mark as a gage for the adjustment of the cutter would be lost. The lug also increases the length of the clampingplate and improves its leverage upon the spring 17. The said spring 17 exerts a constant effort to push the upper end of the clamping-plate 6 outward and is placed under considerable tension when the clamping-sore w is turned inward sufficiently to cause the clamping-plate 6 to impose a strong grip upon the cutter. Now when the screw is reversed the spring will immediately act to push the upper end of the clamping-plate outward, as shown in Fig. 3, and maintain the grip of the lower end of the plate upon the cutter, which will thus be prevented from accidentally shifting its position. If pressure is nowv exerted upon the upper end of the plate-as, for instance, by the thumb-the tension of the spring may be overcome and the plate rocked upon the head of the screw 7 as upon a center, whereby the lower edge of the plate will be disengaged from the cutter, as seen in Fig. 4. The cutter may then he slid one way or the other, as desired. When the cutter has been brought to the right position, the pressure upon the upper end of the plate is relieved and the spring permitted to reassert itself in pushing the plate back into the position shown in Fig. 3, in which itgrips the cutter strongly enough to hold the same in place while the clamping screw is being turned inward, so as to secure the final grip on the cutter, in which position it is shown in Fig. 2.

In the modification shown by Figs. 6 and 7 of the drawings the bevel or slant of the lower edge of the clamping-plate 6 and the bevel of the upper edge of the cutter 12 are increased and the two bevels formed with shallow corrugations or equivalent gripping-surfaces, whereby a stronger grip by the plate upon the cutter is secured not only when the clamping-screw is turned home, but also when it is reversed to permit the cutter to be adjusted, i

at which time the cutter is prevented fr m slipping by the corrugations.

It is apparent that in carrying out my invention some changes from the construction shown and described may be made.

of my invention.

Having fully described myinvention, what 7 I claim as new, and desire to secure by Letters Patent, is

1. In an expansible bit, the combination with the head, transversely-arranged sliding cutter, clamping-plate and clamping-screw thereof, of a spring coacting with the clamp- 1 ing-plate to maintain the grip thereof upon the cutter when the screw is turned back so as to permit the cutter to be adjusted.

2. In an expansible bit, the combination with a head formed with a recess, and with a spring-socket leading out of the bottom of the said recess, of a transversely-arranged sliding cutter adapted to be mounted in the said 7 I would therefore have it understood that I do not limit myself to the exact form illustrated, but cated in the lower end of the :said recess, a hold myself at liberty to make such altera- 5 tions as fairly fall within the spirit and scope 1 leading out of the clamping-plate recess, a

head, a clamping-plate located in the said the cutter, a clam ping-screw passing through the said plate, and a spring located in the said spring-socket, and placed under tension by the clam ping-plate which it operates,when the screw is reversed, to maintain a grip upon the cutter.

3. In an expansible bit, the combination with the head thereof, of a transversely-arranged sliding cutter, a clamping-plate engagingwith the said cutter for holding it against lengthwise movement, a clampingscrew passing through the plate, means for preventing the said plate from swiveling upon the said screw and a spring located above the said screw and coacting with the said plate to cause the same to maintain its grip upon the cutter when the same is turned back so as to permit the cutter to be adjusted.

4. In an expansible bit, the combination with the head thereof, of a transversely-arranged sliding cutter, a clampingplate formed with acentering-lug coacting with the said head, a clamping-screw passing through the said plate which ispreventcd from swiveling upon the said screw by means of the said when the screw is turned back so as to permit the cutter to be adjust-ed.

5. In an eXpa-nsible bit, the combination with a head formed with a clamping-recess, of a transversely-arranged sliding cutter loclamping-plate located in the said recess, and formed with a centering-l u g entering a recess clamping screw passing through the said plate which is prevented from swiveling upon the said screw by means of the said centering-lug, and a spring coacting with the said plate to cause the same to maintain its grip upon the cutter when the screw :is turned back so as to permit the cutter to beadjusted.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

JOSEPH PETER LAVIGNE.

Witnesses:

LILLIAN D. KELSEY, GEORGE D. SEYMOUR. 

